package com.cnswhy.cloud.server.core.utils;

import java.math.BigInteger;
import java.security.MessageDigest;

/**
 * @author HuangHL
 * @date 2015/12/16
 * @see
 */
public class PasswordCoder
{

    // 十六进制下数字到字符的映射数组
    private final static String[] hexDigits = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d",
            "e", "f" };

    private static String key = "ROX834*())23!@#$%^&*JKLSDsdDED";

    /**
     * 把inputString加密
     */
    public static String generatePassword(String inputString)
    {
        return encodeByMD5(inputString);
    }

    /**
     * 验证输入的密码是否正确
     *
     * @param password
     *            加密后的密码
     * @param inputString
     *            输入的字符串
     * @return 验证结果，TRUE:正确 FALSE:错误
     */
    public static boolean validatePassword(String password, String inputString)
    {
        if (password.equals(encodeByMD5(inputString)))
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    /**
     * 对字符串进行MD5加密
     */
    public static String encodeByMD5(String originString)
    {
        if (originString != null)
        {
            try
            {
                // 创建具有指定算法名称的信息摘要
                MessageDigest md = MessageDigest.getInstance("MD5");
                // 使用指定的字节数组对摘要进行最后更新，然后完成摘要计算
                byte[] results = md.digest(originString.getBytes());
                // 将得到的字节数组变成字符串返回
                String resultString = byteArrayToHexString(results);
                BigInteger md5 = new BigInteger(Coder.encryptMD5(resultString.getBytes()));
                resultString = md5.toString(16) + key;
                BigInteger mac = new BigInteger(Coder.encryptHMAC(resultString.getBytes(), key));
                resultString = key + mac.toString(32);
                BigInteger sha = new BigInteger(Coder.encryptSHA(resultString.getBytes()));
                return sha.toString(16).toUpperCase();
            }
            catch (Exception ex)
            {
                ex.printStackTrace();
            }
        }
        return null;
    }

    /**
     * 转换字节数组为十六进制字符串
     *
     * @return 十六进制字符串
     */
    private static String byteArrayToHexString(byte[] b)
    {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++)
        {
            resultSb.append(byteToHexString(b[i]));
        }
        return resultSb.toString();
    }

    /**
     * 将一个字节转化成十六进制形式的字符串
     */
    private static String byteToHexString(byte b)
    {
        int n = b;
        if (n < 0)
            n = 256 + n;
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    public static void main(String[] args)
    {
        System.out.println(encodeByMD5("123456"));
    }
}
